I love playing this game but it is very annoying knowing that when you "Clear" a dungeon it is permanently done...do the bandits/vampires and/or beasts ever come back?

I believe they do.I know that if you clear a cave with a quest to it whatever you need for the quest will be there like "kill such and such in so and so cave"

There seem to be some (very specific quest ones) that don't, but most do.

Oh okay, thanks...

Someone will be along that understands the respawns better than I, but I think you have to stay out of the "cells" for a certain number of ingame days for them to respawn (14 days or 30 days). They may all respawn, but I've gone back to some and they hadn't respawned, however it's possible that I had passed through the cell and reset the timers. Like Grace1957 said some will force a respawn if you've cleared it recently and are sent back for a quest.

Default for cells is 10 days if it wasn't changed by beth.
Default for dungeons that have been cleared is 30 days.

Some ruins in their entirety never respawn again.
Some cells with encounter zones that are set to not reset will never respawn again.

But the majority of areas that I constantly revisit do respawn.

A caveat is that you must make sure that you do not revisit the cell within the above time frame or it will reset the counter.
There are some mods that will decrease the spawn time.

one of my hopes is that bethesda will make all the dungeons respawn, even quest ones because they are normally the best

w00t! I was kinda' right.

And since I've had to post such time frame here more than I can count, I'll add this info to it as well.

The non-quest ones do. The quest ones do not for obvious reasons if you've completed the quest.

Not entirely true. It may respawn, just not completely like it was before. Bleak Falls Barrow respawns, for instance, including the final "big" baddie. But obviously he doesn't have another Dragonstone.